The present invention relates to a head mounted display which displays an image in a visual field of a user by using an image display apparatus.
There have been proposed various methods related to an optical system configuration of a so-called wearable information display apparatus which displays predetermined information by using a goggle type or glasses type head mounted display.
For example, JP-A-2006-3879 describes a method related to a head-mount type image display apparatus which is compact and lightweight although having see-around and see-through mechanisms and which has a large visual field of the outside world and high luminance of electronic images with a low power consumption.
A head mounted display as a wearable device is assumed to be used in a mounted state in daily life work, maintenance work, and the like. Therefore, it is necessary that the head mounted display have a high see-through function in order not to obstruct the user's visual field, and enable high-quality images to be visually recognized even when the sight line of the user moves during work.
Further, in addition to the see-through function, low power consumption for realizing long-time operation, and miniaturization for enhancing the portability and wearability are important for enhancing the convenience of the user.
For example, JP-A-2006-3879 describes that, when, in the image display apparatus, the width of the projected cross-section of a member, which configures an eyepiece window holding section, and which faces the visual axis direction of the user, is set to 4 mm or less, and when the eyepiece window holding section is made thinner than the average human pupil diameter (4 mm), the image display apparatus can obtain a see-through effect because the visual field for the outside world is not completely blocked by the apparatus even when the apparatus is arranged in the visual field.
However, in this case, there is a problem that, when the width of the projected cross-section in the visual axis direction of the user is set to 4 mm which is the same as the pupil diameter, and when the pupil moves with the sight line movement, signal light is not incident on the pupil, so that the image projected in the visual field is invisible or partly invisible.